package templatestrings

import (
	"os"
	"path/filepath"

	"gopkg.in/yaml.v3"
)

type TemplateStrings struct {
	templateStrings map[string]map[string]string
	defaultVariant  string
}

// Load the strings from the specified files into memory
func InitTemplateStrings(stringsDir string, fileExt string, defaultVariant string, otherVariants ...string) (*TemplateStrings, error) {
	ts := &TemplateStrings{
		map[string]map[string]string{},
		defaultVariant,
	}
	// Load strings
	variants := append(otherVariants, defaultVariant)
	for _, variant := range variants {
		if _, ok := ts.templateStrings[variant]; ok {
			// Already loaded
			continue
		}
		variantStrings := map[string]string{}
		f, err := os.Open(filepath.Join(stringsDir, variant+fileExt))
		if err != nil {
			if os.IsNotExist(err) {
				continue
			}
			return nil, err
		}
		err = yaml.NewDecoder(f).Decode(variantStrings)
		if err != nil {
			return nil, err
		}
		ts.templateStrings[variant] = variantStrings
	}
	return ts, nil
}

// Get a string
// input: lang, name or just name (uses default)
func (ts *TemplateStrings) GetTemplateStringVariant(input ...string) (result string) {
	var lang, name string
	if l := len(input); l == 1 {
		// Use default variant
		lang = ts.defaultVariant
		name = input[0]
	} else if l == 2 {
		// Use specified variant
		lang = input[0]
		name = input[1]
	} else {
		// Wrong number of input strings
		return ""
	}
	m, ok := ts.templateStrings[lang]
	if !ok {
		m = ts.templateStrings[ts.defaultVariant]
	}
	result, ok = m[name]
	if !ok {
		result = ts.templateStrings[ts.defaultVariant][name]
	}
	return
}

// Get a func to use for templates
func (ts *TemplateStrings) GetTemplateStringVariantFunc() func(...string) string {
	return func(s ...string) string {
		return ts.GetTemplateStringVariant(s...)
	}
}